<template>
  <el-select
    :value="valueTitle"
    :clearable="clearable"
    @clear="clearHandle"
    :placeholder="placeholder"
    :style="{width:width}"
    :size="size"
  >
    <el-input
      v-if="isFilter"
      class="selectInput"
      :placeholder="filterplaceholder"
      v-model="filterText"
    >
    </el-input>
    <el-option :value="valueTitle" :label="valueTitle" class="options">
      <el-tree
        id="tree-option"
        ref="selectTree"
        :accordion="accordion"
        :data="options"
        :props="props"
        :node-key="props.value"
        :default-expanded-keys="defaultExpandedKey"
        :filter-node-method="filterNode"
        @node-click="handleNodeClick"
      >
      </el-tree>
    </el-option>
  </el-select>
</template>

<script>
export default {
  name: "TreeSelect",
  props: {
    /* 初始值 */
    value: {
      default:'',
    },
    /* 配置项 */
    props: {
      type: Object,
      default: () => {
        return {
          value: "id", // ID字段名
          label: "title", // 显示名称
          children: "children", // 子级字段名
        };
      },
    },
    /* 选项列表数据(树形结构的对象数组) */
    options: {
      type: Array,
      default: () => {
        return [];
      },
    },
    /* 可清空选项 */
    clearable: {
      type: Boolean,
      default: () => {
        return true;
      },
    },
    /* 自动收起 */
    accordion: {
      type: Boolean,
      default: () => {
        return false;
      },
    },
    isFilter: {
      //是否需要搜索
      type: Boolean,
      default: false,
    },
    placeholder: {
      type: String,
      default: "请选择",
    },
    filterplaceholder: {
      type: String,
      default: "检索关键字",
    },
    width:{
      type:String,
      default:"100%"
    },
    size:{
      default:"small"
    }
  },
  data() {
    return {
      filterText: "",
      valueId: '', // 初始值
      valueTitle: "",
      defaultExpandedKey: [],
    };
  },
  watch: {
    // value() {
    //   console.log('this.value---:', this.value)
    //   this.valueId = this.value;
    //   this.initHandle();
    // },
    value:{
        handler(val){
          console.log('val:', val)
          this.valueId = val;
          console.log('this.handle:', this.valueTitle)
          this.initHandle();
        },
        immediate:true,
        deep:true
    },
    filterText(val) {
      this.$refs.selectTree.filter(val);
    },
  },
  
  mounted() {
    this.initHandle();
  },

  methods: {
    // 初始化值
    initHandle() {
      if (this.valueId && this.$refs.selectTree) {
        this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[
          this.props.label
        ]; // 初始化显示
        this.$refs.selectTree.setCurrentKey(this.valueId); // 设置默认选中
        this.defaultExpandedKey = [this.valueId]; // 设置默认展开
      }else{
        this.valueTitle = "";
        this.defaultExpandedKey = [];
      }
      this.initScroll();
    },
    // 初始化滚动条
    initScroll() {
      this.$nextTick(() => {
        let scrollWrap = document.querySelectorAll(
          ".el-scrollbar .el-select-dropdown__wrap"
        )[0];
        let scrollBar = document.querySelectorAll(
          ".el-scrollbar .el-scrollbar__bar"
        );
        scrollWrap.style.cssText =
          "margin: 0px; max-height: none; overflow: hidden;";
        scrollBar.forEach((ele) => (ele.style.width = 0));
      });
    },
    // 切换选项
    handleNodeClick(node) {
      this.valueTitle = node[this.props.label];
      this.valueId = node[this.props.value];
      this.$emit("input", this.valueId);
      this.$emit("getValue", this.valueId);
      this.defaultExpandedKey = [];
    },
    // 清除选中
    clearHandle() {
      this.valueTitle = "";
      this.valueId = null;
      this.defaultExpandedKey = [];
      this.clearSelected();
      this.$emit("input", null);
      this.$emit("getValue", null);
    },
    /* 清空选中样式 */
    clearSelected() {
      let allNode = document.querySelectorAll("#tree-option .el-tree-node");
      allNode.forEach((element) => element.classList.remove("is-current"));
    },
    filterNode(value, data) {
      if (!value) return true;
      return data.name.indexOf(value) !== -1;
    },
  },
//   watch:{
//     value: {
//       handler(val) {
//         console.log('val--:', val)
//         this.valueId = val;
//       },
//       deep: true,
//       immediate: true,
//     },
//   },
};
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item {
  height: auto;
  max-height: 274px;
  padding: 0;
  overflow: hidden;
  overflow-y: auto;
}
.el-select-dropdown__item.selected {
  font-weight: normal;
}
ul li >>> .el-tree .el-tree-node__content {
  height: auto;
  padding: 0 20px;
}
.el-tree-node__label {
  font-weight: normal;
}
.el-tree >>> .is-current .el-tree-node__label {
  color: #409eff;
  font-weight: 700;
}
.el-tree >>> .is-current .el-tree-node__children .el-tree-node__label {
  color: #606266;
  font-weight: normal;
}
.selectInput {
  padding: 0 5px;
  box-sizing: border-box;
}
</style>

